<!doctype html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>阿里巴巴前端校招</title>
	<style>
		* {
			margin: 0;
			padding: 0;
		}

		html,body {
			height: 100%;
		}

		body {
			min-width: 405px;
		}

		.left {
			left:0;
			width: 200px;
			background-color: #456;
		}

		.right {
			width: 300px;
			right: 0;
			margin-left: -30%;
			background-color: #abc;
		}

		.left,.right {
			position: absolute;
			top:0;
			height:100%;
		}

		.main {
			height:100%;
			margin-left:200px;
			margin-right: 300px;
			background-color: #444;
		}

		


	
	</style>
	<script>
</script>
</head>
<body>
	<div class="left">
		左边
	</div>

	<div class="main">
	中间
		
	</div>

	<div class="right">
		右边
	</div>
</body>
</html>